Settings Explained

2. Playback Gain Control. It is mainly used to dynamically control the audio volume, to amplify or to attenuate.
(1) Enable checkbox. Whether the effect is enabled.
(2) Select Effect Strength. Effect Strength is the speed of amplification or attenuation, the stronger the faster the speed and the higher the final volume, the weaker the slower the speed, the closer to the original volume. Recommended medium.
(3) Max Gain. When the volume of the note is too small, in order to uplevel the sound, there may be very large magnification. The higher the value, the louder the volume. But too large will also amplify the noise within the song. Recommended 4 times.
(4) Max Output. This value defines the maximum volume of the PlaybackAGC sound in decibel value, the greater the value the greater the volume, 0 db is the maximum. In order to make the sound softer recommended -1.9 dB.

3. FIR Equalizer. 511-order 10 bands FIR linear equalizer.
(1) Enable checkbox. Whether the effect is enabled.
(2) Select Preset. Here you can select default equalizer presets. When choosing custom, it will follow the user-defined lines drawn.
(3) Linear Equalizer graphic. Will pop up when you touch the graphic equalizer, you can manually adjust the levels of amplification and attenuation of the 10 bands.

4. Convolver
When an impulse response(IR) sample is loaded, music will show the same characteristics of the loaded sample, for example equalizer, surround, reverberation, tube etc.
Make sure SD Card has /ViPER4Android/Kernel/ folder, IR samples will be located there. If folder not exists, you can download latest V4A FX and extract SDCard_V4A.zip.
(1) Enable checkbox. Whether the effect is enabled.
(2) Select Impulse Response. Here you can select and load IR Samples inside /ViPER4Android/Kernel/ folder.
(3) Cross Channel. Brings audio in front of you.

5. Field Surround. It is mainly used to create sound field surround effects. The sound field can be understood as mono field or stereo field.
(1) Enable checkbox. Whether the effect is enabled.
(2) Select Field Surround Strength. This value defines the strength of the field surround effects. The stronger, the stereo effect will be more obvious, the sound will come from left and right sides.
(3) Select Mid Image Strength. This value defines the central vocal intensity. More strongman sound more clear, the weaker the more ethereal sound.

6. Differential Surround also known as Haas effect.
(1) Enable checkbox. Whether the effect is enabled.
(2) Select Delay Time. This value defines the delay(gap) between left and right. The greater the wider the sound.

7. Reverberation. It uses mathematical methods to simulate the environmental feeling sensation. Example a song can be felt playing inside the auditorium, living room, bathroom, and so on.
(1) Enable checkbox. Whether the effect is enabled.
(2) Room Size. This value defines the virtual environment area size. The larger the value, the sound is wider and more echoes.
(3) Sound Field. This value defines the width of the room above, in meters. Assumed that the above room size is 100 square meters, here to set a width of 14 meters, then the length of the room will be 7.14 m.
Therefore, the room size and width defines the aspect ratio of the virtual environment.
The larger the value, the sound coming from both sides will felt more obvious.
(4) Damping Factor. This value defines the humidity of air in the above virtual environment, the moisture vapor in the air will easily absorb the echoes.
So the bigger this value, the less echoes heard.
(5) Wet Signal. This value defines the volume of the simulated environment effect.
(6) Dry Signal. This value defines the volume of the original sound.

For environments with low air humidity such as living room, auditorium and other indoor environment, you can use room size and sound field to define the area of ​​the virtual environment, water vapor content values ​​from 0 to 20, the reverb signal values ​​20 to 50, the proportion of the original signal to take value of about 50.
For environments with high air humidity such as bathroom and other indoor environment that contains a lot of moisture, you can use room size and sound field to define the area of ​​the virtual environment, water vapor content values ​​of 50 to 100, the reverb signal values ​​40 to 80, the proportion of the original signal value of about 50.

8. Dynamic System. It handles the dynamic range of the sound. In other words the bass, treble, and limiting.
(1) Enable checkbox. Whether the effect is enabled.
(2) Select Listening Device. This value defines the headset type connected to the audio jack. If you cannot get the right device for good bass tone, then select Common earphone. Common earphone is a common choice. Recommend Common earphone.
(3) Select Dynamic Bass. This value defines the average dynamic bass, the greater the stronger bass. Recommend 33%.
(4) Tube Simulator(6N1J). This option defines whether to enable tube simulator effect. V4A tube simulator uses a simplified mathematical simulation of tube effect.
If turned on, will greatly reduce high-frequency odd harmonic distortions, while increases even-order harmonic distortions of tube simulator.

11. Master Gate(Limiter). This option is V4A output limiter, its used to prevent overloud clipping distortion.
(1) Ouput Gain. This value defines the main output volume. Its something like a volume control.
(2) Channel Pan: This is output gain ratio for left and right channel.
(3) Limit Threshold. This value defines the limits of waveform amplitude by the limiter, 0 dB is the maximum value.
The smaller the value, the easier to experience audio frequency compression(the smaller the volume), will lose sound details, but can effectively control the final output volume. Recommend 0 db.

< Phone Speaker >
1. Master Power. This option defines whether to enable V4A speaker sound effects, also known as main switch
2. FIR Equalizer. Same as headset equalizer.
3. Convolver. Same as headset convolver.
4. Reverberation. Same as headset reverberation
5. Speaker Optimization. Optimise internal speaker audio quality.
(1) Enable checkbox. Whether the effect is enabled.
6. Extra Loud. eXtra-Loud further amplifies the sound, but is controlled to protect the speaker, will not overload.
(1) Enable checkbox. Whether the effect is enabled.
(2) Select Effect Strength. Effect Strength is the speed of amplification or attenuation, the stronger the faster the speed and the higher the final volume, the weaker the slower the speed, the closer to the original volume. Recommended medium.
(3) Max Gain. When the volume of the note is too small, in order to uplevel the sound, there may be very large magnification. The higher the value, the louder the volume. Recommend infinity.
(4) Max Output. This value defines the maximum volume of the EL sound in decibel value, the greater the value the greater the volume, 0 db is the maximum. Recommend 0db.

4. Audio Reconstruction. It is XHiFi’s core feature, it does the detailing and treble restoring for lossy mp3 audio files. (Currently in adjustment phase, different device may have different experience.)
(1) Enable checkbox. Whether the effect is enabled.
(2) Hi Clarity. This value defines the detailing and treble restoration percentage, the larger the value, the more details of the sound and stronger treble.
For low-end/common earphones, this is not recommended as you may experience high frequency shrills.
For better earphones such as Monster,Philips,Zombie,Sennheiser, recommended value = 30 ~ 50.
For high-end headphones, value depands on headphone cable length. Start with value = 40, value +10 for every 80cm cable length.
For preamp/amp connect to phone. Start with value = 60, value +10 for every 80cm cable length.
For tube amplifier, directly use value = 100.
(3) Lo Contour. The value defines the percentage of bass contour reconstruction over total band. The larger the value, the stronger the bass, but midrange and details will slightly lost.
For earphones recommend value = 50 ~ 70.
For headphones recommend value = 20 ~ 30.

5. Master Gate(Limiter). This option is V4A output limiter, its used to prevent overloud clipping distortion.
(1) Ouput Gain. This value defines the main output volume. Its something like a volume control.
(2) Limit Threshold. This value defines the limits of waveform amplitude by the limitor, 0 dB is the maximum value.
The smaller the value, the easier to experience audio frequency compression(the smaller the volume), will lose sound details, but can effectively control the final output volume. Recommend 0 db.